<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        .bigblock {
            width: 900px;
        }
        .bigblock div{
            width: 300px;
            height: 300px;
            float: left;
        }
        .one {
        background-color: rgb(160, 57, 26);
        }
        .two {
        background-color: blueviolet;
        }
        .three {
        background-color:gold;
        }
        .four {
        background-color: rgb(54, 10, 41);
        }
        .five {
        background-color: yellowgreen;
        }
        .six {
        background-color: rgb(18, 17, 112);
        }
        .seven {
        background-color:pink;
        }
        .eight {
        background-color: goldenrod;
        }
        .nine {
        background-color: black;
        }
        .clearfix::after{
            content: "";
            display: block;
            clear: both;
        }
    </style>
</head>
<body>
    <div class="bigblock clearfix">
        <div class="one"></div>
        <div class="two"></div>
        <div class="three"></div>
        <div class="four"></div>
        <div class="five"></div>
        <div class="six"></div>
        <div class="seven"></div>
        <div class="eight"></div>
        <div class="nine"></div>
    </div>
</body>
</html>